Tuesday, July 31, 2007

Cylinder-less in LA

Posted by
Sean

We're at PEDCO in Santa Fe Springs. We drove here Sunday night, thinking we'd just spend the night in the driveway, but I had forgotten that they run a heavy chain across the driveway when they are closed. So we spent the night parked on the side street just north of the building (map), just a few dozen yards from fellow bus-nut Nick in his RTS. On our way here we passed the oldest operating McDonald's, in Downey, complete with original-style golden arches.

They were ready for us first thing Monday morning, and we pulled in to the shop. Last time we were here, they did all the work with us out in the yard, and I think Virgil had intended to do the same this time, but the shop foreman stuck us in one of the bays. So we are off-line, and they've had to give us a key to the shop so we can get out to go to dinner and walk the dog. At least the weather here is gorgeous right now -- the last time we were here it was miserably hot.

Once we were in the shop, I set to work inside getting the hatch over the turbo off. This involves removing part of the wardrobe that comprises most of the back wall of the bedroom, which, fortunately, was designed for easy (but not necessarily quick) disassembly for exactly this reason. Then the carpet, which is upholstered in and stapled down, needs to come off over the hatch area. Lastly, the hatch needs to be unscrewed and pried up. Well, the last time we did this, which was when we were here two years ago for the last in-frame, we noticed that quite a bit of soot had seeped in around the hatch, and was trapped (fortunately) in the carpet liner. Wanting to avoid continuing this problem, I sealed the hatch down with 3M Fire Barrier Sealant FD 150+.

This is a product that is used by the construction industry to seal wood-to-wood and wood-to-drywall joints in fire-rated walls and ceilings, to curtail smoke and flame spread. Since we were trying to achieve essentially the same result, and since part of the hatch closure was wood-to-wood (the center of the hatch is covered with sheet aluminum, and sits in a steel frame, but the edges are plywood and sit against more plywood subflooring), I reasoned that this product was the best choice. (As a side note, the product is sky blue, making it easy to tell that you haven't missed any spots.)

I am very happy to report that the product performed very well over the last two years, with no penetration of any fumes or soot into the bedroom. However, even though the product is not an adhesive, per se, the liberal amount of sealant made it very difficult to remove the hatch. The hatch was a tight fit to begin with, and required some prying to remove last time, but this time the plywood groaned and threatened to break as I pried on the corner. I ultimately had to work the sharp, thin pry bar around as much of the seam as I could, tapping it with a hammer, in order to cut through the sealant and break enough of the seal to pry the hatch up without breaking it. Even then, I could only access one and a half of the four sides of the hatch with the pry.

All told, removing this one hatch took nearly an hour. Once I had it up, I was prepared to find a disconnected intake duct, or a hole in it, en route to the turbo. However, the duct appeared to be completely intact. In this same time, the PEDCO guys already had the coolant out of the engine and were ready to drop the pan. With the intact air induction, though, I was having second thoughts about what might be wrong. So they pulled the airbox covers off to double-check, and, sure enough, there is dirt in the engine. So now we are all scratching our heads about how it's getting in there. One possibility: the air filter cartridges are not making a good seal against the back of the housing. Once they get everything back together, they'll slap some grease on the back of the housing to see if the filter cartridge displaces it when it is tightened down.

By the end of the day they had all eight cylinders out. One of the cylinders also had a seized ring, which also suggests we ran on low oil pressure at some point. I have asked them to calibrate the dipstick when we are all done, because, as it stands, we are never sure if we have the right amount of oil in the pan. So far the good news is that the main bearings look fine, so even though there is dirt in the oil, it has not done that much damage. I'll probably end up replacing the bearings anyway, and we're waiting on pressure testing to see if the heads will need to be rebuilt. I am betting they will, as the valve guides really don't like dirt.

Since the tear-down was complete in only one day (much quicker than last time -- they put the same two guys on it, and they'd already seen our setup), I am hopeful that we will be done by the end of the week. But I certainly don't want to leave here until we have answered the question of how this dirt is getting in -- two in-frames in two years is more than enough for me.

Sunday evening we had a visit from readers and fellow bus nuts Tom and Donna, who were very kind to buy us dinner. And yesterday I got a call from someone who is looking at Neoplans, and he's talking about coming down for a visit as well, even though it's a long trek from were he is -- near Edwards AFB up in the Mojave desert.

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